Hi Guys,
I have an RB750 infront of a cisco 881G.
I have the pppoe session established on the RB and then a public /30 between the RB and the Cisco.
On the cisco we have configured ip sla, however since it is still able to talk to the RB its not failing over to the 3G.
So what i would like to setup is if the PPPOE session drops, it disables the port the cisco is plugged into.
Have looked thru the forum/wiki but cant find anything.
Any help would be greatly appreciated.
Cheers Matt
On the cisco we have configured ip sla, however since it is still able to talk to the RB its not failing over to the 3G.
So have IP SLA track a port further upstream. Make a /32 route for the RouterBOARDs gateway, for example, point that /32 through the /30, and disable the default route through the /30 based on the tracking object state. You’re mostly there, you’re just watching the wrong thing.
Alternatively look up Netwatch on the Mikrotik wiki and implement its version of IP SLA. But I’d do it on the Cisco router, since that’s the device with dual uplinks.
I’d go for something completely different, though: run OSPF between the RouterBOARD and the Cisco router. On the RouterBOARD introduce a default route into the OSPF area dependent on the router already having a default route via its PPPoE connection (distribute-default=if-installed-as-type1). Then have a floating static on the Cisco router via the 3G modem with a higher administrative distance than the OSPF default it’ll receive (so bigger than 110).
When the PPPoE connection is up the Mikrotik router has a default route, so it announces a default route via OSPF. The Cisco router receives it and uses it. When the PPPoE connection or the link between the Mikrotik and Cisco router dies the OSPF default route is no longer received and the floating static via 3G kicks in. When whatever is broken is fixed the OSPF route is received and used again.
In my opinion that’s cleaner than pinging something (which might suddenly have an ACL applied to it and stop pinging), and also easier for others to understand if you ever ask for help when troubleshooting or train someone else on the equipment.
If you aren’t comfortable with OSPF (though a two routers in one area scenario is very simple and works out of the box) you can also do this with RIP. I’d still prefer that to Netwatch/IP SLA.